Circular saw construction

ABSTRACT

A housing of a circular saw is mounted for displacement in a predetermined direction and has an upper surface. A rotary saw blade is carried by the housing and projects at least in part upwardly of the upper surface thereof. Its general plane is coincident with the predetermined direction. Mounting means is provided for mounting -upwardly proximal to the upper surface of the housing- workpieces which in the aforementioned predetermined direction have at most a predetermined maximum dimension. Supporting plate means is provided on the upper surface of the housing movable with the same and in supporting engagement with a mounted workpiece. According to the invention the supporting plate means comprices a portion which projects beyond the saw blade in the predetermined direction by a distance which at least equals two thirds of the maximum dimension mentioned before to thereby offer additional support to the workpiece.

United States Patent 1 3,695,135

Jagers 5] Oct. 3, 1972 CIRCULAR SAW CONSTRUCTION Primary ExaminerAndrewR. Juhasz 72 Inventor: Leo M E h Rhi Assistant ExammerLeon Grlden it 'igfig us en ne Attorney-Michael S. Striker [73] Assignee: TrennjagerMaschinenfabrik, Eus- [57] ABSTRACT k' h Rh 1 i all me Germany A housingof a circular sawis mounted for displace- [22] July 1970 ment in apredetermined direction and has an upper [21] A l N 57,15 surface. Arotary saw blade is carried by the housing and projects at least in partupwardly of the upper surface thereof. Its general plane is coincidentwith the [30] Forelgn Apphcatlon Pnomy Data predetermined direction.Mounting means is provided July 23, 1969 Germany ..P 19 37 321.8 formounting upwardly proximal to the upper surface of thehousing-workpieces which in the afore- [52] US. Cl. ..83/455,83/485,143/47 E mentioned predetermined direction have at most a [51]Int. Cl. ..B26d 7/02 d t rmined maximum dimension. Supporting plate 1Fleld of Search 47 means is provided on the upper surface of the housing83/488, 489, 48 movable with the same and in supporting engagement witha mounted workpiece. According to the inven- [56] References Cted tionthe supporting plate means comprices a portion UNITED STATES PATENTSwhich projects beyond the saw blade in the predetermined direction by adistance which at least equals 2,933, Meyer E two thirds of the maximumdimension mentioned be- Kohlel et a]. F X fore to thereby fferadditional upport to the workpiece.

8 Claims, 8 Drawing Figures INVENTOR zrl/ ATTORNEY PAIENTEIJIIBI I9 23.695.135

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ATTORNEY CIRCULAR SAW CONSTRUCTION BACKGROUND OF THE INVENTION Theinvention relates generally to circular saw constructions and moreparticularly to a circular saw capable of sawing through metallicworkpieces. Still more particularly the invention relates to a circularsaw capable of sawing through cold metallic workpieces having in thedirection in which the sawing cut is being made, a dimension greaterthan the diameter of the saw blade itself.

Saws of this type are already known and are usually intended for makinghigh-speed cuts. In these known constructions the saw blade togetherwith its housing is advanced with reference to and beneath the workpiecewhich itself is clamped or otherwise secured on the frame or support ofthe saw. The workpiece is supported on a plate mounted on the frame orsupport of the saw itself and the housing is moved--together with thesaw blade--beneath this place and thereby the workpiece.

Experience has shown that with saws constructed according to the priorart workpieces having substantial dimensions in the direction in whichthe cut is being made can be sawed with high speed only if care is takenthat the saw blade is not subjected to forces exerted upon itself by theworkpiece in direction transversely to the cutting direction. It istherefore already known to provide a gliding guide beneath thesupporting plate for the workpiece and to spring-bias the housing of thesaw against this guide to stabilize it during the cut. However, thisconstruction is relatively complicated and therefore subject tomalfunctions andto other difficulties. Aside from this it is of coursenecessarily expensive to produce and therefore to sell.

SUMMARY OF THE INVENTION It is, accordingly, an object of the presentinvention to provide a circular saw of the type under discussion whichis not possessed of the disadvantages outlined above with respect to theprior art.

More particularly it is an object of the present invention to providesuch a circular saw which makes it possible to make high-speed cutsthrough material of the type and configurations already outlined above,but whose construction is much simpler than that known from the priorart and whose reliability is therefore also increased.

In pursuance of the above objects, and others which will become apparenthereafter, one feature of the invention resides, in a circular saw, in acombination which briefly stated comprises housing means mounted fordisplacement in a predetermined direction and having an upper surface. Arotary saw blade is carried by the housing means and projects at leastin part upwardly of the upper surface thereof. Its genera] plane iscoincident with the predetermined direction of advancement ordisplacement of the housing means. Mounting means is provided formounting upwardly proximal to the upper surface work pieces having inthe aforementioned direction at most a predetermined maximum dimension.Finally, and according to the present invention, supporting plate meansis provided on the upper surface of the housing means movable with thelatter and being in supporting engagement with a mounted workpiece. Thissupporting plate means comprises a portion which projects beyond the sawblade in the aforementioned predetermined direction and by a distancewhich at least equals two thirds of the aforementioned maximumdimension. This assures that throughout the entire cut the workpiecewill always be supported by the projecting portion of the supportingplate means, thereby eliminating the possibility that transverse forcescould act upon the saw blade with the resulting disadvantages.

According to another embodiment the mounting means provided for mountingof the workpieces is of such construction that it presses from aboveagainst the workpiece and thereby presses the latter against the uppersurface of the supporting plate means. F urthermore, it is advantageousit the supporting plate means, which may but need not be of metallicmaterial, is provided with a slot elongated in the aforementionedpredetermined direction so that the saw blade can project upwardlythrough it with the result that portions of the blade are also locatedat opposite axial sides of the blade and provide further support for theworkpiece. In this case the portions which are located at opposite axialsides of the saw blade are in suitable manner supported on or by thehousing means to prevent them from becoming deflected, for instanceunder the weight of the workpiece.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a diagrammaticend-elevational view illustrating one embodiment of the invention;

FIG. 2 is a similarly diagrammatic side-elevational view of FIG. 1;

FIG. 3 is a diagrammatic top-plan view of the embodiment in FIGS. 1 and2 showing the saw blade in one position with reference to the workpieceto be cut;

FIG. 4 is a view similar to FIG. 3 but showing the saw blade of thatembodiment in a. different position with reference to the workpiece tobe cut;

FIG. 5 is a view similar to FIG. 1 but illustrating a further embodimentof the invention;

FIG. 6 is a view similar to FIG. 2 but of the embodiment shown in FIG.5;

FIG. 7 is a view similar to FIG. 3 but showing the embodiment of FIG. 5in the same position as that shown in FIG. 3; and

FIG. 8 is a view similar to FIG. 4 and corresponding in the illustratedposition to that shown in FIG. 4, but showing the embodiment of FIGS.5-8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing now the drawing indetail, and firstly the embodiment in FIGS. 1-4, it will be seen thatthe circular saw according to the present invention comprises a base 12on which there is mounted a sliding guide arrangement 7 of the so-calleddovetail type which is already well known in the art and requires nofurther discussion. It is pointed out, however, that the guide 7 guidesthe housing 6 of the circular saw for displacement in a predetermineddirection which is indicated by the arrow A (see FIG. 2). Furtherprovided on the base 12 is an upwardly extending frame portion 2 whichcarries in the region of its upper end two mounting jaws 3 and 4. Thejaw 4 is stationary in so far as the direction indicated by the arrow A(or the opposite direction) is concerned, whereas the jaw 3 can be movedtowards and away from the jaw 4 as indicated by the arrow B (see FIG.2). The jaws 3 and 4 can be moved apart from one another by a maximumdistance a (see FIG. 2) which corresponds to the maximum dimension of aworkpiece to be clamped between them. The workpiece is identified withreference numeral 1 and it will be appreciated that ordinarily thisdimension a will be the width of the workpiece and that the length ofthe workpiece is to be understood as being normal to the dimension a,such as indicated in FIG. 1.

The housing 6 carries the rotatable saw blade 5 whose axis of rotationis diagrammatically shown in FIG. 2. Details of the saw blade 5, itsmounting and its drive, both of the latter being accommodated in thehousing 6, is not thought to be necessary not only because they arewholly conventional and any suitable constructions may be utilized, butalso because they do not themselves form a part of the presentinvention. The direction of rotation of the saw blade 5 is indicated inFIG. 2 with the curved arrow D.

According to the present invention there is mounted on the upper surface6a of the housing 6 a supporting platepreferably of metallic materialand planar9 which moves with the housing 6. The plate 9 should berelatively sturdy so that when a weight is placed on it it will not bendor be deflected. According to the invention, however, what is essentialis that the blade 9 comprise a portion which projects forwardly of thesaw blade 5 by a distance b which is at least equal to two thirds of thedimension a. This is indicated in FIG. 2 where a comparison of thedimensions a and b will show that. In other words, the length of theprojecting portion of the plate 9, that is the length or dimension bshown in FIG. 2, must be at least equal to two thirds of the maximumdimension a of workpieces l which can be accommodated and clampedbetween the jaws 3 and 4. Incidentally, it is not believed to benecessary to discuss how the jaw 3 can be moved and secured withreference to the jaw 4, again because this is well known and forms nopart of the present invention.

If the plate 9 is of metallic material as is usually the case, then itsupper surface is hardened and ground or otherwise made suitably planar,such upper surface being located in a plane common both to it and to asurface of the frame portion 2 on which the workpiece 1 can in partrest. Thus, as far as the longitudinal extension of the workpiece 1 isconcerned, a portion of the workpiece l rests on the forwardlyprojecting portion of the plate 9 whereas another portion of theworkpiece 1 longitudinally spaced from the first-mentioned portion restson the aforementioned surface of the frame 2. It is clear withoutdetailed discussion that the surface of the frame 2 is stationary withreference to the workpiece whereas the projecting portion of the plate 9moves with reference to the workpiece 1 as the plate 9 moves with thehousing 6 and the saw blade 5, which and exertion of various forces uponthe saw blade 5 transversely to the cutting plane are avoided.

FIG. 3 shows the illustrated and thus-far discussed embodiment in oneposition of the saw blade 5 with reference to the workpiece 1, namelywhere a cut at right angles to the elongation of the workpiece 1 is tobe carried out.

It shouldbe mentioned parenthetically that the motor for effecting therotation of the saw blade 5 may be mounted on or in the housing 6 andthat the advancement of the housing 6 with the blade 5 is carried out bymeans of a conventional spindle 8 which may be rotated by anon-illustrated motor in known manner. Again it is emphasized that noneof this is a part of the present invention and is in any case well knownto those skilled in the art.

FIG. 4 shows the embodiment of FIGS 1 and 3 when the saw blade 5 is tobe used to cut into and through the workpiece l in a direction otherthan at a right angle to the elongation of the workpiece 1. For thispurpose the guide 7 together with the housing 6 and the plate 9 can bepivoted about an upright or vertical axis 13 (diagrammaticallyindicated) in the direction of the curved arrow C which is in the planeof abutment of the stationary jaw 4. The latter has a cut-out 4a soconfigurated that it permits an entry into the cut-out of portions ofthe saw blade 5 at any angle between 0 and 45. The workpiece 1 may beadvanced lengthwise in the direction of the arrow D in suitable mannerand of course the housing 6 with the saw blade 5 and the supportingplate 9 will be advanced in the direction of the arrow A as before.

Coming to the embodiment illustrated in FIGS. 5-8 it is emphasized thatthis is quite similar to that of FIGS. 1-4 which differs from it only inthat the movable jaw has been constructed and arranged in a differentmanner and that the plate 9 has been replaced with a somewhatdifferently configurated plate. Otherwise identical reference numeralshave been employed in FIGS. 5-8 to indicate components already discussedwith reference to FIGS. l-4.

Keeping this in mind it is pointed out that in FIGS. 5-8 the movable jawof the mounting means is identified with reference numeral 14 andmovable in a fluid-operated-preferably hydraulically actuated cylinder15 in a direction which is inclined to the vertical and positioned in avertical plane in the direction of advancement A of the housing 6. Thus,and this is particularly clearly shown in FIG. 6, the jaw 14 can pressthe workpiece l downwardly against the upper surface of the supportingplate which here is identified with reference numeral 9a. The cylinder15 is mounted on a bridge or guide 1 1 which in turn is secured to theframe portion 2 and which extends in the direction of advancement A ofthe housing 6; the mounting may be accomplished by means of screws 10 orthe like and is such that the cylinder 15 can be displaced lengthwise ofthe bridge or support 1 1.

In this embodiment, as already mentioned before, the plate member 9a issomewhat different from the plate member 9 in FIGS. 1-4. Specifically,in the embodiment of FIGS. 5-8 the plate member 9a is provided with aslot extending in the direction of the arrow A, as indicated withreference numeral 9b in FIG. 7, and the saw blade 5 projects upwardly inpart through this slot 9b. In view of this the plate member 9a of coursehas auxiliary portions 9a and 9a" which are located at opposite axialsides with reference to the saw blade 5 and which thus project toopposite axial directions relative to the saw blade 5. They serve asadditional support for the workpiece and are supported-that is both ofthemrigidly by the housing 6 in such a manner that the plate member 9ais a rigid unit. In other words, flexing or deflecting of the portions9a and 9a" with reference to one another-which would not occur in theabsence of the slot 9bmust be prevented. This, again, prevents theexertion of lateral forces upon the saw blade 5, just as does theprimary feature of the invention, namely that in the embodiment of FIGS.5-8 again a portion of the blade 9a projects forwardly of the saw blade5 with such portion having an extension or elongation corresponding tothe dimension a indicated in FIG. 2.

FIG. 7 is of course a view illustrating the embodiment of FIGS. 58 inthe same operational position as FIG. 3 illustrates the embodiment ofFIGS. 1-4, whereas FIG. 8 is a view similar to FIG. 4 but illustratingthe embodiment of FIGS. 5-8.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofconstructions differing from the types described above.

While the invention has been illustrated and described as embodied in acircular saw, it is not intended to be limited to the details shown,since various modifications and structural changes may be made withoutdeparting in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can be applying current knowledge,readily adapt it for various applications without omitting featuresthat, from the standpoint of prior art fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims:

1. In a circular saw, in combination, support means defining a gap andhaving at opposite sides of said gap respective upper surfaces locatedin an at least substantially horizontal common plane; means mounted fordisplacement in said gap intermediate said upper surfaces in apredetermined direction; a rotary saw blade carried by said movablemeans projecting at least in part upwardly beyond said common plane andhaving a general plane coincident with said predetennined direction;mounting means including at least two mounting elements movable apart bya maximum mounting distance in which they can engage and retain againstmovement a workpiece which extends across said a and is su rt d on saidu er surfaces, such work pi ce havingq safd direction a dimension whichat most equals said maximum mounting distance; and supporting platemeans carried by said movable means and having an upper face located insaid common plane for engaging and supporting said workpieceintermediate said upper surfaces, said supporting plate means comprisinga portion projecting beyond said saw blade in said predetermineddirection by a distance which equals at least two thirds of said maximummounting distance, and said supporting plate means being movable withsaid movable means relative to and beneath said workpiece so that thelatter is supported in said gap by said upper face of said portion whilebeing sawed by said saw blade.

2. In a circular saw as defined in claim 1, said movable means beingpivotable about a vertical axis with reference to said support means.

3. In a circular saw as defined in claim 1, said upper face of saidsupporting plate means being flat.

4. In a circular saw as defined in claim 1, said supporting plate meansconsisting of metallic material.

5. In a circular saw as defined in claim 1, at least one of saidmounting elements urging the mounted workpiece into engagement with saidsupporting plate means.

6. In a circular saw as defined in claim 1, said saw blade having twoaxial sides facing transversely of said predetermined direction; andwherein said supporting plate means comprises additional portions whichrespectively project beyond said axial sides transversely of saidpredetermined direction in said gap so as to support correspondingportions of the mounted workpiece.

7. In a circular saw as defined in claim 6, said supporting plate meanshaving a slot elongated in and coincident with said predetermineddirection, and said saw blade projecting through said slot.

8. In a circular saw as defined in claim 6, said additional portionsbeing associated with said movable means in a sense supporting themagainst deflection.

1. In a circular saw, in combination, support means defining a gap andhaving at opposite sides of said gap respective upper surfaces locatedin an at least substantially horizontal common plane; means mounted fordisplacement in said gap intermediate said upper surfaces in apredetermined direction; a rotary saw blade carried by said movablemeans projecting at least in part upwardly beyond said common plane andhaving a general plane coincident with said predetermined direction;mounting means including at least two mounting elements movable apart bya maximum mounting distance in which they can engage and retain againstmovement a workpiece which extends across said gap and is supported onsaid upper surfaces, such workpiece having in said direction a dimensionwhich at most equals said maximum mounting distance; and supportingplate means carried by said movable means and having an upper facelocated in said common plane for engaging and supporting said workpieceintermediate said upper surfaces, said supporting plate means comprisinga portion projecting beyond said saw blade in said predetermineddirection by a distance which equals at least two thirds of said maximummounting distance, and said supporting plate means being movable withsaid movable means relative to and beneath said workpiece so that thelatter is supported in said gap by said upper face of said portion whilebeing sawed by said saw blade.
 2. In a circular saw as defined in claim1, said movable means being pivotable about a vertical axis withreference to said support means.
 3. In a circular saw as defined inclaim 1, said upper face of said supporting plate means being flat. 4.In a circular saw as defined in claim 1, said supporting plate meansconsisting of metallic material.
 5. In a circular saw as defined inclaim 1, at least one of said mounting elements urging the mountedworkpiece into engagement with said supporting plate means.
 6. In acircular saw as defined in claim 1, said saw blade having two axialsides facing transversely of said predetermined direction; and whereinsaid supporting plate means comprises additional portions whichrespectively project beyond said axial sides transversely of saidpredetermined direction in said gap so as to support correspondingportions of the mounted workpiece.
 7. In a circular saw as defined inclaim 6, said supporting plate means having a slot elongated in andcoincident with said predetermined direction, and said saw bladeprojecting through said slot.
 8. In a circular saw as defined in claim6, said additional portions being associated with said movable means ina sense supporting them against deflection.